I would like to create a query that calculate a whighted average of wofls based on number of birds for the first 5 rows.Is there a way to use sqldf to limit the calculation to the first 5 rows?
Here ...

I am trying to concatenate 2 columns of a data-frame in R using sqldf command. However, it treats them as numeric and sums them up. I looked at the solution to a similar question on stackoverflow but ...

I have a script in R that works when I run it manually. I am building
a web application that will allow non R users to run the application. To create the web application I used Rwui.
The application ...

I have a SQLite database pisa06.db created from a data frame. I would like to read variables (columns) from this database file selectively without actually loading into memory. I know I can do it with ...

My question involves how to skip metadata in the beginning of a file when importing data into R. My data is in .txt format where the first lines
are metadata describing the data and these need to be ...

I am unable to use fn$ within a for loop. When I test it with one variable, (x = "a_ind") I am able to successfully run a loop. However, when I add multiple variables via (c("a_ind",...)) it no longer ...

I'm using the sqldf R library to write to an sql database using the command:
dbWriteTable(db, table_id, as.data.frame(table_df))
where db is the sql database file, table_id is the name of the table ...

I am looking for a function to concatenate two strings inside SQLDF in R, that works like paste(), but could not find any. The reason for doing that is I want to concatenate two columns while joining ...

I have problems multiplying numbers of an external variable in sqldf
In the projection of the SQL statement I would like to multiply the value of a column with an external float variable input$euro ...

I need to join two tables on the colum name. They come from different excel spreadsheets which I didn't create. I imported both sheets into R tables using the function read.xls from the gdata package.
...

I have three data frames dbase, data and dcode.
I want to copy the rows from dbase to data when dbase$idbase = data$iddata and add based on dcode the names of dcode when dbase$nr matches the number ...

I am using read.csv.sql from the package sqldf to try and read in a subset of rows, where the subset selects from multiple values - these values are stored in another vector.
I have hacked a way to ...